PrEP Failure Case Underscores Importance of Regular HIV Testing

An Interview With Elske Hoornenborg, M.D.

By Terri Wilder, M.S.W.

From TheBodyPRO

March 17, 2017

Elske Hoornenborg, M.D. (Credit: Terri Wilder)

A case of HIV transmission in a person who was adherent to pre-exposure prophylaxis (PrEP) was one of the most discussed studies at CROI 2017. We've seen two previous cases of PrEP failure where HIV was able to transmit because of drug resistance. This was the first case of PrEP failure that did not involve drug resistance, making it unclear why or how transmission happened. Terri Wilder, M.S.W., spoke with Elske Hoornenborg, M.D., the lead author of the study, at CROI 2017, in Seattle.

Elske Hoornenborg, M.D.: A person was enrolled in our PrEP Project. He was using daily PrEP and reported excellent adherence. And then, he was HIV negative all the way; he got a few rectal infections that we treated. But after eight months of PrEP use, he got symptoms of a urinary tract infection. We tested him for HIV, and we found that he was antibody positive.

However, he was antigen negative. HIV viral load was negative at that point. We tried to establish a diagnosis, so we tested for proviral DNA in his PBMCs [peripheral blood mononuclear cells] and in sigmoid biopsies. But there was no viral DNA that we could find.

Because there was no diagnosis of HIV infection, we decided to stop his PrEP and try to establish a diagnosis. Three weeks later, his viral load became positive. So, there was indeed an HIV infection. We started him on therapy.

Advertisement

TW: Can you talk a bit more about his adherence to the medication?

EH: We checked adherence in three different ways: self-reported, pill counts, and dried blood spots. We collected the dried blood spots at month six and month eight. Month eight was the moment of seroconversion. And they showed very high intracellular levels of tenofovir diphosphate [Viread], comparable with very good, excellent adherence.

TW: Can you maybe describe in more detail how you were able to detect the HIV in this person?

EH: Yeah. It was really hard to establish a diagnosis because there was no HIV viral load at the point of seroconversion. There was no antigen. So, that really put us in a dilemma how to go forward.

We also did Western blot testing at the moment of seroconversion, which showed only one single gp160 band, which is very atypical for an acute HIV infection.

TW: He had some history of reoccurring sexually transmitted infections [STIs].

EH: Yes.

TW: Do we think this history may have anything to do with this?

EH: This was a guy who was on PrEP. He was very well aware of his risks. He had several partners; he reported, like, 50 partners per month. Most were condomless. Most were receptive. And, yes, he did acquire a few rectal STIs, which is not surprising if you look at his sexual behavior.

TW: What do you think this case report really means for the general scientific community about PrEP efficacy?

EH: I'm a very strong believer in the efficacy of PrEP. If you see worldwide the many thousands of people who are taking PrEP, who are happy to have a fulfilling sex life without fear of HIV, I think PrEP is an immensely important discovery.

Now, we have one breakthrough infection with a wild-type virus. This case had no resistance mutations, and that made it different. That's different from the other two cases that were reported previously. But it's only one case, compared with the several thousands, tens of thousands, of people who use PrEP. I think we have to conclude and communicate to our people that PrEP is very effective -- if you take it well.

It also underscores the importance of having your HIV tests done every three months while you take PrEP. It underscores, yeah, that we should educate people about use of condoms in addition to PrEP, not only for HIV, but also to protect them from STIs.

TW: In terms of his care right now?

EH: After establishing a diagnosis, we started him on combination antiretroviral therapy. He had an undetectable viral load after one month, and he's doing very well.

TW: Great. Thank you so much.

EH: You're welcome.

This transcript has been lightly edited for clarity.

Terri L. Wilder, M.S.W., is a director of HIV/AIDS education and training in New York City.

This article was provided by TheBodyPRO. It is a part of the publication The 24th Conference on Retroviruses and Opportunistic Infections.

No comments have been made.

Add Your Comment:

(Please note: Your name and comment will be public, and may even show up in Internet search results. Be careful when providing personal information! Beforeadding your comment, please read TheBody.com's Comment Policy.)

Please do not modify the following input field.

Your Name:

Your Location:

(ex: San Francisco, CA)

Your Comment:

Characters remaining:

Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.

TheBodyPRO is a service of Remedy Health Media, 461 Fifth Avenue, 14th Floor, New York, NY 10017. TheBodyPRO and its logos are trademarks of Remedy Health Media, LLC, and its subsidiaries, which owns the copyright of TheBodyPRO's homepage, topic pages, page designs and HTML code. General Disclaimer: TheBodyPRO is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through TheBodyPRO should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, consult your health care provider.